Drive mechanism



Oct. 8, 1968 Filed March 21, 1966 F. L. KASTELIC ETAL DRIVE MECHANISM 5 Sheets-Sheet 1 FlG.l

INVENTORS FRANK L. KASTEL/C WILLIAM H. WE/DMAN QBWWWWW ATTORNEYS Oct. 8, 1968 F. L. KASTELlC ETAL 3,404,881

DRIVE MECHANISM Filed March 21, 1966 5 Sheets-Sheet 2 H6 4 nv VENTORS FRANK L. KASTELIC W/LL IAM H. WE/DMAN BWWMW A T TORNE Y5 Oct. 8, 1968 F. L. KASTELIC ETAL 3,404,831

DRIVE MECHANISM Filed March 21, 1966 5 Sheets-Sheet 5 INVENTORS FRANK L. KASTEL 1c WILLIAM H. WE/DMAN BWMW ATTORNE Y8 United States Patent,

' DRIVE MECHANISM Frank L. Kastelic, Cleveland, and William H. Weidman,

Maple Heights, Ohio, assignors to Harris Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed Mar. 21, 1966, Ser. No. 536,112

16 Claims. (Cl. 271-8) ABSTRACT OF THE DISCLOSURE A sheet feeder includes driven parts operable to effect feeding of sheets from a pile. The drive means for driving the parts of the feeder includes a drive member which is abruptly stopped during the operation of the feeder. A shock-absorbing drive unit is drivingly connected to the feeder and to the drive member. The shock-absorbing drive unit includes a driven member drivingly connected to the drive member to abruptly stop upon stopping of the drive member and a feeder drive member drivingly connected with the feeder and free for movement relative to the driven member thereof due to the inertia of the parts of the feeder when the drive member is abruptly stopped.

The present invention relates to a shock absorbing drive mechanism, and particularly to a shock absorbing drive mechanism for use in a drive between machine units which operate successively on material and in a timed relation, such as a printing press and a feeder for feeding material to the press.

A printing press and feeder for feeding sheet material to the press are driven in timed relation so that a sheet advanced by the feeder arrives at the press at the proper time and in a registered relationship. The feeder includes a tape table for advancing the sheets to a registering mechanism. The registering mechanism operates to register the sheets prior to their being advanced into the press and includes front stops for engaging the leading edge of the sheeet and feed wheels which engage the sheeet after it has been registered against the front stops and which operate to feed the sheets into the press. The registering mechanism also includes a sheet detector operable to sense the absence of a sheet or a sheet that has been fed improperly. When the detector senses the absence of a properly fed sheet, the detector is operable to disengage a clutch in the drive between the feeder and the press to stop the feeder. The output of the clutch is abruptly stopped by suitable brake means upon disengagement of the clutch. The abrupt stopping of the output member of the clutch causes an abrupt stopping of the mechanism in the feeder causing shock forces to be set up in the feeder and drive, and which are particularly great in large installations where the mass of feeder parts is relatively great. These shock forces cause excessive wear and possible destruction of parts of the feeder mechanism. Moreover, sheets which are being fed along the tape table tend to continue moving even though the feeding mechanism is stopped and this causes sheets to become disarranged, skewed and out of timed relation-ship.

Accordingly, the principal object of the present invention is the provision of a new and improved drive mechanism for a sheet feeder and including a drive member which is abruptly stopped and a shock absorbing drive unit between the abruptly stopped drive member and the feeder and operable to allow overrunning or coasting of the feeder, even though the drive member is abruptly stopped, and thereby minimizing the shock forces created in the feeder and the drive therefor and minimizing disarrangement and skewing of sheets when the feeder is stopped.

3,404,881 Patented Oct. 8, 1968 A further object of the' present invention is the provision of a new and improved feeder drive having a drive member which is abruptly stopped to effect a stopping of the feeder and including a shock absorbing drive unitbetween the abruptly stopped drive member and the feeder which allows for an overrunning or a coasting of the feeder when the drive member stops and which incorporates a spring member against which the feeder overruns or coasts and which functions to stop the overrunning of the feeder and thereby, in a sense, cushions the stopping of the feeder.

Another object of the present invention is the provision of a new and improved feeder drive, as noted in the next preceding paragraph, wherein the spring member acts between a drive member which moves upon overrunning of the 'feeder and a second member Whichis abruptly stopped with the drive member compressing the spring.

A further object of the present invention is the provision of a new and improved drive mechanism for use in a drive for a printing press and a feeder which advances sheets to a register mechanism from which the sheets are advanced to the press, and wherein the feeder and register mechanism are abruptly stopped upon disengagement of a clutch in the drive thereto and wherein the drive between the clutch and the feeder is constructed so as to permit limited overrunning or coasting of the feeder due to the inertia of the moving parts thereof without corresponding movement of the register mechanism, and which is operable upon re-engagernent of the clutch to prevent operation of the feeder until the register mechanism has operated a sufiicient amount to restore the predetermined timed operation thereof with the feeder.

A still further object of the present invention is the provision of a new and improved drive mechanism, as noted in the next preceding para-graph, wherein the drive between the clutch and feeder includes a shock absorbing unit including first and second drive members operatively connected with the register mechanism and the feeder, respectively, and wherein the drive unit is operable to allow for movement of the second member which is connected to the feeder, relative. to the first member which is connected with the register mechanism, when the first member is abruptly stopped and is further operable when the clutch is re-engaged to allow for movement of the first member relative to the second member an amount equal to the first amount of movement therebetween to restore the timed driving relationship.

A further object of the present invention is the provision of a new and improved drive mechanism which includes a shaft rotably supporting a gear and an arm member fixedly secured to the shaft and a pin member carried by the gear and engageable with the arm member to effect rotation of the arm member and the shaft upon rotation of the gear and a spring means acting between the arm member and a part rigidly connected to the gear and biasing said arm member into a predetermined position relative thereto and permitting cushioned" movement of the arm member away from the pin upon rotation of the shaft member without a corresponding rotation of the gear member.

Further objects and advantages of the present invention will be apparent to those skilled in the art to which it relates from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings forming a part of this specification, and in which:

FIG. 1 is a schematic side elevational view of a printing press and feeder therefor and embodying the present invention;

ICC

1 .FIG. 2 is a schematic view of a portion of the "apparatus of FIG. 1, looking at the apparatus of FIG. 1 approximately along the line 2--2 thereof;

FIG. 3 is a schematic view of a portion of the drive mechanism shown in FIG. 2;

7 FIG. 4 is a fragmentary sectional view of the apparatus shown in FIG. 1, taken approximately along the section line 44 thereof and showing parts in elevation;

FIG. 5 is an elevational view of the mechanism shown in FIG. 4, looking at the mechanism of FIG. 4 from the left; and

FIGS. 6, 7 and 8 are schematic views illustrating different operative positions of the mechanism shown in FIG. 5.

The present invention provides an improved shock absorbing drive mechanism which is particularly useful in a drive for a feeder for advancing sheet material to a printing press and wherein certain parts are abruptly stopped resulting in shock forces being applied to the feeder and drive therefor and disarrangement of the sheets being fed. The present invention is directed to minimizing these sh'ock forces and the disarran-gement of the sheets. The drive mechanism of the present invention may be used in any environment where it is desired to cushion such shock forces and particularly in any sheet fed rotary machine. However, to illustrate the preferred embodiment of the present invention, the drawings show a printing press and feeder mechanism, generally designated 5. p

The printing press and feeder mechanism 5 comprises a sheet feeder unit 6 and a printing press 7 which receives sheets advanced by the feeder unit 6. The feeder unit 6 is operable to feed sheets from a pile P. The top sheets of the pile are raised from the pile by raising suckers 8 which engage the rear edges of the topmost sheet of the pile and raise it to forwarding suckers 9 which grip the sheet and move the sheet forwardly in a direction toward the printing press 7. The leading edges of the sheets are advanced by the forwarding suckers 9 to a suitable conveyor arrangement, generally designated 10, which advances the sheets to a register mechanism 11. The conveyor arrangement 10 comprises a tape table and includes a plurality of driven tapes and idler wheels 11a which cooperate with the tapes to feed the sheets along the tape table. The sheets are advanced along the tape table in a stream or lapped relationship.

The register mechanism 11 includes front stops 12 which move into the path of the sheets and against which the leading edges of the sheets are advanced to properly front register the sheets. The register mechanism 11 also includes a suitable mechanism, not shown, for side registering of the sheets. After an individual sheet is registered both front and side, the front stops 12 retract and feed rollers 13, 14 move to engage the opposite sides of the sheet to feed the sheet to a feed cylinder 16.

The feed cylinder 16 has grippers 17 thereon which engage the leading edge of the sheet and convey the leading edge of the sheet to an advance cylinder 18 which also has grippers 19 thereon which engage the leading edge of the sheet and carry the sheet to an impression cylinder 20 of the printing press 7. The impression cylinder 20 also has grippers thereon which cooperate with the grippers on the advance cylinder 18 to take the sheet therefrom and carry the sheet through the printing nip 21.

The apparatus 5 includes a suitable drive mechanism, designated 25, for driving the printing press 7, register mechanism 11, and feeder 6 in a predetermined timed registered relation. The drive mechanism includes a gear 26 which is driven in timed relation to the printing press and which meshes with a gear 27 fixedly carried on a shaft 28. The shaft 28 carries another gear 29 fixed thereon which meshes with a gear 30 rotatable about a shaft 31. It should, therefore, be clear from the above that upon driving of the press, the gears 26, 27, 29 and 30 rotate.

The gear 30 may be drivingly connected to rotate the shaft 31 upon rotation thereof by a clutch mechanism designated 35. The clutch mechanism 35 includes an input clutch member 36 fixedly connected to the gear 30, and an output clutch member 37 which is fixedly carried on the shaft 31. The clutch 35 includes a driving latch or pawl 38 which is pivotally carried on the output clutch part 37 and which may be pivoted relative thereto in any well-known manner. Specifically, a cam member 39 carried on a shaft 39a is moved from the full-line position shown in FIG. 3 to the dotted-line position to move the pawl 38 to its disengaged position. The member 39 moves the pawl 38 to a disengaged position out of engagement in a driving notch 40 in the input clutch part 36 and holds it out of driving position. A spring 41 biases the driving latch or pawl 38 so as to be engaged in the notch 40 and pulls the pawl 38 into the notch. There is only notch 40 in the input clutch part 36 and, thus, the gear 30 and the shaft 31 may be drivingly connected in only one predetermined angular relative position therebetween.

As noted above, when the clutch 35 is engaged, the shaft 31 is driven upon rotation of the gear 30. The shaft 31, when driven, is effective to drive the register mechanism 11 and feeder 6. The shaft 31, as shown schematically in FIG. 3, carries cams 42, 43 for operating the stops 12 and the feed wheels 13, 14 and are connected therewith in any suitable manner. Due to this drive arrangement including clutch 35, the register mechanism 11 and printing press are driven in a timed relation so that the sheets are advanced to the advance cylinder 16 at the proper time.

The shaft 31 also carries a gear 45 drivingly connected to the feeder 6 and which meshes with an idler pinion gear 46. The gear 46, in turn meshes with a driven member or gear 47. The gear 47 is drivingly connected through a suitable shock absorbing drive unit 50 to a feeder drive shaft 51. The shaft 51 carries a pinion gear 52 which meshes with a pinion gear 53 fixedly carried by a shaft 54. The shaft 54 extends to the feeder and comprises an input drive shaft for the feeder mechanisms, not shown, since the specifics thereof do not form a part of the present invention. A drive shaft 54a driven from shaft 54 is shown in FIG. 1 and extends vertically and is drivingly connected to the tape conveyors forming a part of the conveyor arrangement 10 to effect driving thereof.

The apparatus 5 also includes a sheet detector which is located adjacent the advance cylinder 16 and which detects the presence or absence of a properly fed sheet. The detector is operable to effect a rotation of shaft 39a and movement of pawl 38 to its dotted position causing disengagement of the clutch parts 36, 37. The detector could actuate a solenoid or be connected in some mechanical manner, not shown, to effect disengagement of the clutch. Moreover, a manual trip-off also may be provided for. Disengagement of the clutch 35, of course, stops the drive to the shaft 31, thereby stopping the drive to the feeder 6 and register mechanism 11. The detector may take many forms, but preferably is of the well-known type which is operable to sense the absence of a sheet and/or a sheet out of registry or out of proper alignment, such as a sheet may be skewed or may have been fed too soon and is, therefore, in advance of its proper position.

The detector, as noted above, of course is operable to disengage the clutch 35 and thereby interrupt the drive to the shaft 31. A suitable braking means 61 is associated with the shaft 31 so as to effect an abrupt stopping of the shaft 31, when the clutch 35 is disengaged. This braking means 61, shown schematically in FIG. 3, comprises a pivotal latch member 62 and a disk member 63 fixedly connected to shaft 31 and having a notch 64 therein for receiving the latch member 62. When the latch 62 is engaged in the notch 64, the shaft 31 is abruptly stopped. The latch 62 is moved into the notch 64 upon rotation of shaft 39a. Shaft 39a carries a crank arm 65 which moves from its full-line position to its dotted position to move the latch 62 into notch 64 when the shaft 39a is rotated. A spring 66 biases the latch 62 out of the notch 64 and is effective to move the latch 62 out of the notch when the arm 65 is withdrawn from the dotted position shown in FIG. 3. The latch 62 is moved downwardly, as viewed in FIG. 3, so as to abruptly stop shaft 31 upon movement of pawl 38 by clutch 35 to its disengaged position.

The clutch 35 is preferably disengaged when the shaft 31 is in an angular position, such that the front stops 12 are up, that is, located in the path of sheet movement, and the feed wheels 13, 14 are apart in a non-feeding position. As described above, the feed wheels '13, 14 advance the sheet into the grippers on the feed cylinder 16, and thus any substantial movement of the feed wheels 13, 14 toward their feeding position when the clutch has disengaged will cause the next sheet fed by the feed wheels 13, 14 to the feed cylinder 16 to be delivered thereto before the grippers 17 thereon are in position to engage the sheet. Thus, it is desired to abruptly stop the cam shaft 31 so that the register mechanism 11 remains in driving registry with the feed cylinder 16.

When the clutch 35 is disengaged and the cam shaft 31 is abruptly stopped and the drive to the feeder 6 is thus interrupted, the feeder mechanism tends to continue to operate or overrun the cam shaft 31 and register mechanism 11 due to the inertia of the moving parts contained in the feeder 6. This is particularly true where the speed and mass of the moving parts of the feeder 6 is great. This tendency of the feeder, unless compensated for, causes backlash and shock forces to be applied to the various drive parts between the clutch 35 and the feeder 6 and, at times, could result in movement of the shaft 31 which would destroy the operative registered relationship and predetermined timed driving relationship between the feeder and the press and also could result in destruction of certain parts of the feeder 6 and the drive thereto. Moreover, the tape conveyors are abruptly stopped and the sheets being conveyed thereby tend to continue to move because of the inertia thereof. This results in a disarrangement of and/or skewing of the sheets. Furthermore, the left end of the tapes, as viewed in FIG. 1, is driven'and the right end thereof is trained around idler rollers, and when the left end of the tapes stops abruptly, the right end tends to continue causing the belts to stretch or slip. This also adds to the disarranging of the sheets.

In accordance with the present invention, the drive unit 50 operates to minimize these shock forces and the disa-rrangement of the sheets and solves the above-noted problems. The drive unit 50 which is connected between the gear 47 and the shaft 51 is operable to cushion the above-mentioned shock forces and may be referred to as a shock absorbing drive unit. The drive unit 50 comprises a feeder drive member in the form of an arm member 70 which is keyed at 71 to the shaft 51. The arm member 70 has portions which extend radially from the shaft 51. The arm member 70 is driven directly from the gear 47 and by means of a pin drive which includes a driving pin 73. The driving pin 73 is fixedly secured to a portion of the gear 47 and engages an edge portion of the arm 73 and, specifically, it engages in'a recess 75 in the left edge of the arm 70, as viewed in FIG. 5. When the arm 70 is engaged by the pin 73, it is, of course, driven directly from the gear 47 through the pin 73 and effects a driving of the shaft 51. The gear 47 has an enlarged hub portion which includes projecting portions 80, 81 located on opposite sides of the shaft 51. The portions 80, 81 define a recess 82 therebetween and through which the arm 70 extends. The outer end of the portion 81 is interconnected with one end of the arm 70 by means of a spring connection, generally designated 90.

The spring connection-90 comprises a rod member 91 slidably connected for movement relative to the arm 70 by a suitable connection 92 and pivotally connected to the portion 81 by a connection 93. 'A suitable coil spring 95 encircles the rod and extends between the connections 93, 92 and effects a biasing of the arm portion 81 and the arm 70 in opposite directions about the shaft 51; 7

The operation of the drive unit will be apparent from a description of FIGS. 6-8 of the drawings. FIG. 6 shows the drive unit in its normal driving position when the clutch 35 is engaged and with the pin73 driving the arm 70 and, in turn, the shaft 51. In the event that shaft 39a is rotated either by manual trip or by the detector sensing the absence of a properly fed sheet, theclutch mechanism 35 is disengaged and the shaft 31 is abruptly stopped by brake means 61. This, of course, abruptly stops the rotation of the gear 45 and the gear 46, as well as the gear 47 which meshes with the gear 46. When the gear 47 abruptly stops rotating, the pin 73 carried thereby, of course, also stops rotating.

As noted hereinabove, however, the parts and mechanism of the feeder have a substantial amount of inertia and they tend to continue to rotate even though the clutch 35 has been disengaged. Since these parts tend to continue to rotate, the shaft 51 tends to continue to rotate due to the inertia of this mechanism and the drive unit 50 is operable to permit the shaft 51 to rotate due to this inertia. Thus, the drive unit 50 is operable to allow the feeder 6 to overrun or coast relative to the register mechanism 11. When the feeder 6 overruns or coasts in this manner, the arm 70 moves against the bias of spring 95 which cushions the stopping of the feeder and applies a force to the arm member 70 to stop the arm member and thus limit the overrunning of the feeder 6.

FIG. 8 shows the position of the arm 70 after the shaft 51 has rotated and with the feeder 6 fully stopped. It should be apparent, of course, that the spring 95 has been compressed due to the movement of the arm 70, while the arm portion 81 connected with the gear 47 has not rotated after disengagement of the clutch 35.

Upon re-engagement of the clutch 35, the register mechanism 11 must operate a small amount before operation of the feeder 6 in order to return the register mechanism 11 and feeder 6 to their proper timed driving relationship. FIG. 8 illustrates the position of the parts of the drive unit 50 after the clutch 35 is disengaged and the feeder 6 fully stopped. When the clutch 35 is engaged, the gear 47 is again rotated. However, the pin 73 must rotate through an arc, designated Y in FIG. 8, before it will engage the arm 70. This are, of course, is of an angular distance which equals the angular distance which the arm member 70 rotated because of the overrunning of the feeder 6. The portion 81 connected with the spring also rotates, due to the fact that it is connected with the gear 47, and thus the pin 73 and portion 81 rotate relative to the arm 70 and relative to the shaft 51 when the clutch is re-engaged. This relative rotation occurs, as noted above, through a distance which is equal to the angular distance of movement of the arm 70 when the clutch was disengaged. This relative movement returns the spring 95 to its original condition. The pin 73, once it engages the arm 70, then continues rotation of the arm 70 with the gear 47 so as to effect a driving of the feeder 6. The register mechanism 11 and feeder 6 are thus restored to their previous driving registered relationship.

From the above, it should be apparent that the drive unit 50 is operable to permit the feeder 6 to overrun or coast relative to the register mechanism 11 and also operates to cushion the shock forces therein when the clutch 35 is disengaged. Since the feeder and the tapes of the conveyor arrangement 10 come to a slow stop, the sheets being conveyed by the tapes are slowly stopped under control, thus minimizing the tendency thereof to continue to move due to inertia and thereby minimizing disarrangement of the sheets. When the clutch 35 is re-engaged, the drive unit 50 provides for restoring the predetermined timed driving relationship between the register mechanism 11 and feeder 6, due to the fact that the register mechanism operates while the feeder 6 does not until the pin 73 moves through an arc equal to the are through which the arm member 70 rotated when the clutch was disengaged.

It should be apparent from the above that applicants have provided a highly improved drive mechanism and that certain modifications, changes, and adaptations may be made therein by those skilled in the art to which it relates, and it is intended hereby to cover all such modifications, changes, and adaptations coming within the scope of the appended claims.

Having described our invention, we claim:

1. An apparatus comprising a sheet feeder having driven parts operable to effect feeding of sheets from a pile, drive means for driving said parts including a drive member abruptly stopped during operation of the feeder, a shock absorbing drive unit drivingly connected to said feeder and to said drive member and including a driven member drivingly connected to said drive member to abruptly stop upon stopping of said drive member, and a feeder drive member drivingly connected with said feeder and free for movement relative to said driven member due to the inertia of the parts of said feeder when said driven member is abruptly stopped.

2. An apparatus as defined in claim 1 further including a spring means acting against said movement of said feeder drive member relative to said driven member and yielding upon said relative movement and operable to stop movement of said feeder parts and said member due to inertia.

3. An apparatus as defined in claim 2 wherein said spring acts between said feeder drive member and said driven member and is compressed due to said relative movement, and further including a drive connection between said driven member and said feeder drive member operable to maintain said feeder drive member stationary while said driven member is driven a distance to compensate for the movement of said feeder drive member due to inertia.

4. An apparatus as defined in claim 3 wherein said feeder drive member comprises an arm member keyed to a feeder. drive shaft, said driven member comprises a gear member rotatable relative to said shaft and having a driving connection with said arm member allowing for said free movement due to inertia, and said spring member acts between said arm member and said gear.

5. An apparatus comprising a sheet feeder having driven parts operable to effect feeding of sheets from a pile, drive means for driving said parts of said feeder including a clutch having an input clutch member and an output clutch member and being disengageable to interrupt the drive to said feeder, means for abruptly stopping said output clutch member upon disengagement of said clutch, and a cushion drive unit drivingly connected with said out ut clutch member and said feeder and operable to drive said feeder when said clutch is engaged and operable to provide for said feeder to coast to a stop when said clutch is disengaged and said output clutch member abruptly stopped.

6. An apparatus as defined in claim 5 wherein said cushion drive unit comprises a driven member drivingly connected to the output of said clutch and which stops abruptly upon disengaging of said clutch, a feeder drive member drivingly connected with said feeder to drive said feeder upon driving thereof, and means drivingly interconnecting said driven member and said feeder drive member and operable to allow for movement of said feeder drive member relative to said driven member a first distance when said driven member is abruptly stopped and to allow for movement of said driven member relative to said feeder drive member by an amount equal to said first distance when said clutch is reengaged.

7. An apparatus as defined in claim 5 wherein said feeder drive member comprises an arm member keyed to a feeder drive shaft and said driven member comprises a gear rotatable on said shaft, a pin drive connection between said gear and arm with said arm movable relative to said pin, and a spring member acting between said arm and gear biasing said arm into engagement with said pin.

8. An apparatus as defined in claim 5 wherein said feeder includes a plurality of tapes for receiving sheets from said parts and effecting feeding of the sheets along a tape table.

9. An apparatus comprising a printing press for print ing on sheet material, a feeding mechanism for feeding sheet material to said printing press, a drive mechanism for driving said feeding mechanism in a predetermined timed registered relation with said press, said drive mechanism including a clutch having an input clutch member and an output clutch member engageable in a single relative angular position to effect driving of said feeding mechanism in a predetermined timed relation with said press and disengageable to stop driving of said feeding mechanism, means for abruptly stopping said output clutch member upon disengagement of said clutch, and a cushion drive unit forming a part of said drive mechanism and drivingly connected with said output clutch member and providing for said feeding mechanism to overrun said output clutch member when said clutch is disengaged and when said clutch is re-engaged providing for driving of said output clutch member before driving of said feeding mechanism.

10. The apparatus as defined in claim 9 wherein said cushion drive unit comprises a driven member drivingly connected to the output member of said clutch and which stops abruptly upon disengaging of said clutch, a feeder drive member drivingly connected with said feeding mechanism to effect operation of the feeding mechanism upon driving thereof, and drive means drivingly interconnecting said driven member and said feeder drive member and operable to allow for movement of said feeder drive member relative to said driven member a first distance when said driven member is abruptly stopped and to allow for movement of said driven member relative to said feeder drive member a second distance equal to said first distance when said clutch means is re-engaged.

11. An apparatus as defined in claim 10 wherein said feeder drive member comprises an arm carried on a feeder drive shaft and said driven member comprises a gear rotatably carried on said shaft, and spring means acting between said arm and gear and againsnt movement of said arm relative to said gear upon disengagement of said clutch.

12. An apparatus as defined in claim 11 wherein said arm member is driven from said gear by means of a pin having an abutting relationship with said arm member, and said spring biases said arm member toward engagement with said pin.

13. An apparatus as defined in claim 9 further including a sheet register mechanism operable to receive sheets from said feeder and register the sheets and advance the sheets from a registered position toward the press, means for drivingly connecting said register mechanism with said output clutch member, said register mechanism abruptly stopping upon abrupt stopping of said output clutch member, and said cushion drive unit being operable to allow said feeder to overrun said register mechanism due to the inertia of the parts thereof when said output clutch member is disengaged.

14. An'apparatus as defined in claim 13 wherein said register mechanism includes front stops movable to engage the leading edge of a sheet, feed wheels movable into feeding engagement with a sheet to feed the sheet toward the press and a sheet detector for actuating said clutch when said front stops are in the path of the sheet and the feed wheels in a non-feeding position, and said cushion 9 drive unit being operable to allow for overrunning of said feeder while said feed wheels remain in their non-feeding position and said front stops are located in the path of the sheets.

15. An apparatus comprising a first drive member comprising a gear, a second drive member comprising a shaft rotatably supporting said gear, an arm member fixedly secured to said shaft and extending radially therefrom, a pin member carried by said gear and having an abutting engagement with said arm member to effect rotation of said arm member and said shaft, spring means acting between said arm member and a part rigidly connected to said gear and biasing said arm member into engagement with said pin and permitting movement of said arm member away from said pin upon rotation of said shaft member without a corresponding rotation of said gear, means 10 for stopping said gear abruptly, and means driven by said shaft and having high inertia efiecting movement of said shaft and arm against said spring when said gear is abruptly stopped.

16. An apparatus as defined in claim 15 wherein said means driven by said shaft comprises a sheet feeder, and said gear is driven through a clutch having an output clutch member, and means for abruptly stopping said output clutch member upon disengagement of said clutch.

References Cited UNITED STATES PATENTS 10/1956 Miller 74-411 2,916,948 12/1959 Reid 74-411 RICHARD E. AEGERTER, Primary Examiner 

